In a related-art elevator system, a car velocity, an amount of movement of a car, and a floor reference position are detected by a detection device. A safety controller compares a result of detection by the detection device to an abnormality determination threshold value of the car velocity, which is set for a position of the car, to determine occurrence of an open-door running abnormality. Further, the safety controller calculates a landing reference position for landing of the car and a distance for determination from the landing reference position to the car position. The abnormality determination threshold value is set so as to decrease as the distance for determination increases. Further, the abnormality determination threshold value is set based on the car position and a deceleration for stopping the car at a predetermined position (see, for example, Patent Literature 1).
Further, in a related-art elevator apparatus, a braking capability check mode for checking a braking capability of a brake device under a state in which no passenger is present in the car is included in operation modes of an elevator control device. In the braking capability check mode, the car which is currently running at a rated velocity is brought to an emergency stop by the brake device so that a deceleration of the car and a braking distance are measured (see, for example, Patent Literature 2).
Further, a related-art characteristic evaluation device for an elevator brake automatically evaluates characteristics of the brake based on a running distance of the car over an interval between time points at each of which a derivative of the car velocity changes when the car is forcibly stopped, and transmits a result of the evaluation to a monitoring center (see, for example, Patent Literature 3).
Still further, in a related-art safety system for an elevator, detection plates are provided at specific positions in a hoistway. The car is provided with a car-position sensor configured to detect the detection plates. Distance information indicating the specific positions at which the detection plates are provided and an interval therebetween is stored in a database. A safety controller detects, based on an output from the car-position sensor, that the car position matches with the specific position. Further, the safety controller calculates the car velocity for each interval from elapsed time for each interval and the distance information, and compares the car velocity to an excessively large velocity determination curve (see, for example, Patent Literature 4).